1. Field of the Invention
The present invention provides a method for the purification of a crude lactam mixture by means of melt crystallization. In the present invention, the crude lactam mixture contains laurolactam as the target component and secondary components. As the mixture is cooled, the laurolactam selectively crystallizes and can be removed from the mixture.
2. Discussion of the Background
Laurolactam is typically removed from the secondary components in a crude lactam mixture by means of a multistage distillation. Due to the high boiling point of laurolactam, during distillation a high vacuum has to be applied. However, the thermal stress on the mixture in every evaporation step leads to the decomposition of the material of value. Thus, the method heretofore employed in the art described above, leads to a reduction in the overall yield of laurolactam.